Portable containers of the type for holding and dispensing fluids are commonly used in the fields of beverages and liquid preparations, such as liquid cleansers, soaps, conditioners, shampoos, lotions, and the like. A typical portable container for holding liquid contents is the type having made of glass or plastic and that includes a neck that extends downwardly from a mouth to a shoulder that extends outwardly and downwardly to a container body defined by a sidewall having a closed bottom. Since containers of this type are reusable, and often designed to be reusable, skilled artisans have devoted considerable effort toward the development of closure assemblies useful for not only closing the container mouth but also effectuating withdrawal of the liquid contents of the container. However, current efforts have not yielded entirely acceptable results. For instance, some closure assemblies are rudimentary and inadequate. While others are needlessly expensive, difficult to construct, structurally complex, and fail to adequately close the container mouth while at the same time enabling a convenient withdrawal of the liquid contents from the container. Given these and other deficiencies inherent in the art, the need for continued improvement is evident.